Intravascular imaging of atherosclerosis

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• Prof.Dr.Ir. Ton van der Steen
• Wednesday 07 November 2012, 17:00-18:00
• Berridge Room, Level 5, Addenbrookes Hospital, University Dept of Radiology,Cambridge CB2 0QQ.

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INTRAVASCULAR IMAGING OF ATHEROSCLEROSIS

Prof.dr.ir. Ton van der Steen1,2

1 Thoraxcenter Biomedical Engineering, Erasmus MC Rotterdam, the Netherlands; 2 Interuniversity Cardiology Institute of the Netherlands, Utrecht, The Netherlands. Corresponding e-mail: a.vandersteen@erasmusmc.nl

Intravascular ultrasound (IVUS) is a technology that uses an ultrasound element on the tip of a catheter[1, 2]. This catheter is advanced through the groin into the coronary arteries. In this way a tomographic image of the vascular wall and atherosclerotic plaques can be produced. The steering of the ultrasound beam can be done by mechanically rotating a single ultrasound transducer, or electronically, using an array of 64 elements in the tip. Historically is has been used to assess the level of occlusion, the atherosclerotic plaque burden and the native size of the vessel. This information can be used to decide to treat or not and to determine the diameter and length of the stent to be used for treatment. It has also been used extensively to determine if the stent was well deployed. The composition and morphology of an atherosclerotic lesion are currently considered more important determinants of acute coronary ischemic syndromes that the degree of stenosis³. When a lesion is unstable, it can rupture and cause an acute thrombotic reaction. An unstable plaque can be characterized by a lipid core that is covered by a thin fibrous cap, which has been locally weakened by inflammatory cells. The last decade serious effort has been put in developing IVUS towards identifying these unstable plaques. This lecture will focus on the development of measuring the elastic properties of the plaque as a marker for plaque instability⁴ and measuring the vascularization in the plaque⁵, which plays an important role in the pathogenesis of unstable plaque. Furthermore the role of combined ultrasound/light catheters will be discussed[6, 7]. These will allow to image the luminal plaque at a resolution of around 10 µm, while maintaining the full overview. Furthermore photoacoustics and combination of NIR spectroscopy and imaging will be possible. Technology development in the elements, the echomachines and the signal processing will be presented as well as their validation and the role of IVUS to provide imaging biomarkers in natural history studies and trials for the development of new cardiovascular drugs[8, 9].

REFERENCES

[1] A. F. W. van der Steen, E. I. Cespedes, C. L. de Korte, S. G. Carlier, W. Li, F. Mastik, C. T. Lancee, J. Borsboom, F. Lupotti, R. Krams, P. W. Serruys, and N. Bom, “Novel developments in intravascular imaging,” in Proceedings 1998 IEEE Ultrasonics Symposium, pp. 1733-1742. [2] Vascular Ultrasound. A.F.W. van der Steen, Y. Saijo eds. Tokio: Springer, 2004. [3] J. A. Schaar, J. E. Muller, E. Falk, R. Virmani, V. Fuster, P. W. Serruys, A. Colombo, C. Stefanadis, W. S. Casscells, P. R. Moreno, A. Maseri, and A. F. W. van der Steen, “Terminology for high-risk and vulnerable coronary artery plaques,” European Heart Journal, vol. 25, pp. 1077-1082, 2004. [4] C. L. de Korte, M. J. Sierevogel, F. Mastik, C. Strijder, J. A. Schaar, E. Velema, G. Pasterkamp, P. W. Serruys, and A. F. W. van der Steen, “Identification of atherosclerotic plaque components with intravascular ultrasound elastography in vivo – A Yucatan pig study,” Circulation, vol. 105, pp. 1627-1630, 2002. [5] D. E. Goertz, M. E. Frijlink, D. Tempel, L. C. van Damme, R. Krams, J. A. Schaar, F. J. Ten Cate, P. W. Serruys, N. de Jong, and A. F. van der Steen, “Contrast harmonic intravascular ultrasound: a feasibility study for vasa vasorum imaging,” Invest Radiol, vol. 41, pp. 631-8, 2006. [6] A. F. van der Steen, R. A. Baldewsing, F. Levent Degertekin, S. Emelianov, M. E. Frijlink, Y. Furukawa, D. Goertz, M. Karaman, P. T. Khuri-Yakub, K. Kim, F. Mastik, T. Moriya, O. Oralkan, Y. Saijo, J. A. Schaar, P. W. Serruys, S. Sethuraman, A. Tanaka, H. J. Vos, R. Witte, and M. O’Donnell, “IVUS beyond the horizon,” EuroIntervention, vol. 2, pp. 132-42, 2006. [7] S. Garg, P. Serruys, M. v. d. Ent, C. Schultz, F. Mastik, G. v. Soest, A. v. d. Steen, M. Wilder, J. Muller, and E. Regar, “First use in patients of a combined near infra-red spectroscopy and intra-vascular ultrasound catheter to identify composition and structure of coronary plaque,” EuroIntervention, vol. 5, pp. 755-756, 2010. [8] P. W. Serruys, H. M. Garcia-Garcia, P. Buszman, P. Erne, S. Verheye, M. Aschermann, H. Duckers, O. Bleie, D. Dudek, H. E. Botker, C. von Birgelen, D. D’Amico, T. Hutchinson, A. Zambanini, F. Mastik, G. A. van Es, A. F. van der Steen, D. G. Vince, P. Ganz, C. W. Hamm, W. Wijns, and A. Zalewski, “Effects of the direct lipoprotein-associated phospholipase A(2) inhibitor darapladib on human coronary atherosclerotic plaque,” Circulation, vol. 118, pp. 1172-82, 2008. [9] C. A. G. Van Mieghem, E. P. McFadden, P. J. de Feyter, N. Bruining, J. A. Schaar, N. R. Mollet, F. Cademartiri, D. Goedhart, S. de Winter, G. R. Granillo, M. Valgimigli, F. Mastik, A. F. van der Steen, W. J. van der Giessen, G. Sianos, B. Backx, M. A. M. Morel, G. A. van Es, A. Zalewski, and P. W. Serruys, “Noninvasive detection of subclinical coronary atherosclerosis coupled with assessment of changes in plaque characteristics using novel invasive imaging modalities,” Journal of the American College Of Cardiology, vol. 47, pp. 1134-1142, 2006.

This talk is part of the Cambridge Radiology Forum series.

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• Berridge Room, Level 5, Addenbrookes Hospital, University Dept of Radiology,Cambridge CB2 0QQ
• Cambridge Radiology Forum

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